(1) Field of the Invention
The present invention relates to a high current cable for 50/60 Hz TN-S mains.
(2) Description of Related Art
It was and is believed that in electrical indoor installations consistent wiring according to TN-S ensures an operation free of ground current. This is as a result of guiding the grounding conductor separately from the distribution point in the building, i.e. that the grounding conductor is to be without current during operation.
However, measurements in the vicinity of indoor installations has shown, again and again, the opposite, namely, that the grounding conductor has high currents in spite of TN-S installation, especially when the phase, neutral and ground conductors are installed as single conductors next to each other. As shown in theoretical and practical tests, these ground conductor currents are caused by induction. Depending on the cross section of the conductor the currents induced in the grounding conductor can reach significant levels i.e. between 10% and 20% of the highest phase current. Furthermore, cables installed this way also induce currents in adjacent metal constructions like cable lines, air, water and/or gas pipes, iron reinforcements etc. The results are unexplainable increases in the magnetic field and problems with EMC and corrosion.